Large camera and display screens and switching thereto



June 7, 1966 H. A. MlcHLlN 3,255,372

LARGE CAMERA AND DISPLAY SCREENS AND SWITCHING THERETO FIG 2 INVENTORJune 7, 1966 H. A. Nucl-LIN 3,255,372

LARGE CAMERA AND DISPLAY SCREENS AND SWITCHING THERETO Filed March 2,1961 2. Sheets-SheetI 2 United States Patent O Filed Mar. 2, 1961, Ser.No. 139,020 10 Claims. (Cl. 313-92) This application is acontinuation-in-part of application Serial No. 170,866, filed June 28,1950, now abandoned.

This invention relates to switching by systematic electron impacting ofelements to eiect switching to conductors in flat screens withelectroluminescent phosphors or photoelectric substances therebetween.

The principle of the invention is in ythe use of a screen of spacedelectrical conductors, such as copper or transparent coating of stannouschloride or the like, lying in a plane in said screen, with each saidconductor having one area thereof near to only one area of one differentsaid conductor, and with electroluminescent phosphors therebetween. Suchscreens have the advantages of being thin, portable, and capable ofbeing made theoretically of unlimited size. To effect such advantageseasily, novel switching elements are longitudinally Iarranged so thatthey can be close to such screen, each of such elements normallyinsulative and capable of becoming conductive on electron impacting, aplurality of electron beams with each said beam controlled to scan andimpact predetermined elements in a predetermined sequence.

The electroluminescent phosphors :uscd in this invention can tbe thosedisclosed in Patent No. 2,254,957, which are in contact with conductorsand which emit light immed-iately on flow of current therethrough;herein transparent crystals of carborundum are disclosed as emittingwhite light at 10 volts using 0.1 milliampere of current; this and othercrystals are disclosed with different activators of manganese, copper,or silver to produce different color emission. Other phosphors,electrophotoluminescent, were disclosed by Gudden .and Pohl in 1920 aseffecting an enhanced light emission on application of electric fieldsto a phosphor, in dielectric, previously excited by ultra-violet -rays.Excited hex ZnOzZn irnrnersed in oil was caused to emit a sharp burst oflight on application of electric iield of 15,000 v./cm. in a givendirection, and on reapplication of this field in a change of directionof 90 caused another burst of light; this is disclosed on page 393,Luminescence of Solids, by Leverenz, published on June l2, 1950, citingprevious reports. Destriaus article on page 701 in Philosoph-icalMagazine, vol. 38, October 1947, discloses that calcium tungstate andruby in a thin layer produces electroluminescence at a voltage of 200 to400 volts. General Electric Review, July 1954, pages 46-49, disclosescopper activated zinc sulfide to give a surface brightness of about onefoot lambert when excited -by 110 volts and 60 cycles, and of 25-footlamberts when it is excited at 3000 volts and kilocycles per second.These sources clearly establish that the voltage across theelectroluminescent cells need not be excessive and is well withi'n therange of voltage variations permitted by the variable conductanceelements impacted by the electron beam. An example of varia-bleconductance elements is disclosed in Physical Review, February 1949,page 472, as electron bombarded -amorphous silica transmitting currentas much as 100 times that in the bombarding electron beam. PatentsNumbers 2,540,490 and 2,740,837 discloses variable conductancesubstances. The electroluminescent phosphors noted above are for exampleonly as others are disclosed in different publications such as FaradaySociety Transactions, vol. 35, January 1939, page 227; Proceedings ofthe I.R.E., vol. 43, No. 12, December 1955, pages 191141940. Increasingthe number of frequencies of varying electr-ic elds applied toelectroluminescent phosphors effect an increase in electroluminescence;which is disclosed on page 229 and 232 of Faraday Society Transactions,supra, and pages 1917-1918 of the Proceedings of the I.R.E., supra,discloses others. Patent No. 2,243,828 discloses a mixture of differentcolor emitting phosphors to produce a resultant color; therefore, wheredifferent color emitting phosphors emit a different relative intensityof light on application of different frequencies, a different resultantcolor will be effected on each different frequency of electric fieldsapplied to the same mixture of different color emitting phosphors. Theelectroluminescent phosphors described above can be used in differentspecies of the screen. Photoconductive cadmium suliide is discussed inthe RCA Review, vol. XII, No. 3, part 1, September 1951, page 354.

Other objects and advantages of my invention may be had by referring .tothe following description and claims when taken in connection with thelaccompanying drawings wherein:

yFIGURE 1 is a lschematic illustration of the electronic switching ofelectric energy to elemental areas in a screen.

FIGURE 2 schematically illustrates an electromphotoluminescent screen ora color screen.

FIGURE 3 schematically illustrates electronic switching of electricenergy in different directions to cells in a screen.

FIGURIE 4 schematically illustrates strips of conductors to transmitelectric energy to elemental. areas in a screen.

FIGURE 5 schematically illustrates a novel species of electroluminescentcell.

FIGURE `6 schematically illustrates the electroluminescent cell inFIGU-RE 5 adapted to the screen in FIG- URE 1.

The electron 'bombardment induced conductance elements are hereinafterreferred to as variable conductance insulators. v

Referring to FIGURES 5 and 6 .to illustrate an example of the invention.A photocathode film 25, such as photoemissive cesium oxide, is placedbetween an electroluminescent phosphor 26 Which, preferably, can be thecurrent transmission electroluminescent phosphors noted above, withtransparent conducting layers 27 (IFIG- URE 5) and conductors 28 (FIGURE6) on each side thereof, and a variable conductance insulator 29separating conductors; a metal base 30 is impressed with a high positivepotential from source 31 to accelerate electrons thereto; a negativepotential is transmitted from source 31 to the .photocathode lm 25 as asupply of electrons, and one side of the variable conductance insulator29. Glass layer 32 separates the photocathode layer 25 from theelectroluminescent cell, insulation 4layer 33 separates the variableconductance insulator 29 from the metal base 30. The space 34 is invacuum to effect an easier acceleration of the photoelectrons emittedfrom the photocathode to ybombard the variable conductance insulator 29to penetrate it. The glass plate 35 protects the free side of theelectroluminescent cell. Conductors 15 and 16 (see FIGURE l) providesthe initial potential difference to effect the initial production ofelectroluminescence.

The initial production of light emission is in an intensity in4accordance with the voltage and current transmitted therethrough. Thislight irradiated on the photocathode 25 would effect a photoelectronemission therefrom to impact the variable conductance insulator 29accelerated =by the high positive potential on the metal plate 30,thereby negative electricity is caused to be transmitted to theelectroluminescent cell to effect a greater electroluminescence which inturn activates the photocathode 25 further to emit a greater volume ofphotoelectron emission and thus forrns a cascade increase in lightemission in accordance with time.

Lowering the potential difference to the variable conductance insulatorwill lengthen the time necessary to reach peak electroluminescence andelectric current ow. This process can be started again by reversing thepotential on the conductor 16 so as to neutralize the potentialtransmitted from the potential difference source 31 by creating apositive potential equal to that on the other side of the variableconductance insulator and the electroluminescent phosphor 26. And sostop the flow of current through the variable conductance insulator 29and through the electroluminescent phosphors thereby stopping theelectroluminescence. i

FIGURE 6 schematically illustrates each cell of FIG- URE 5, which can becells L and M in screen of FIGURE 1. Electric potential differencethrough each of the conductors and 16 initiate the electroluminescenceas is described below for FIGURE 1.

The method of invention is to systematically and selectively scan eachone of a plurality of variable conductance insulators electricallyconnected to a common electric energy source and to a separate conductorso as to systematically and selectively transmit electric energy tosuccessive separate volume of photoelectric, electroluminescent, orradiant energy excited electroluminescent substances so at to convert anoptical image into a train of signal energy, or to convert a train ofsignal energy into an optical image.

Referring to the drawings. FIGURE 1 illustrates by way of example theinvention, cathode ray switching tubes A, B, C and D employing aplurality of variable conductance insulators 1, 2, 3, 4, 5, and 6. Thesaid tubes comprise an evacuated container 7 enclosing said plurality ofvariable conductance insulators, an electron gun 8 for generating,focusing, and accelerating a beam of high velocity electrons towards thesaid plurality of Variable conductance insulators, and a set ofelectrostatic defiecting plates 9 and 10 in tubes A and C, and delectingplates 9 and 11 in tubes B and D, which deflecting plate 9 derives itsdeflecting signals from the vertical and horizontal deflecting signalgenerators 12 and 13 to cause the beam of electrons 14 to scan each ofthe said plurality of variable conductance insulators in turn. Theelements in tubes A and B can be readily combined in one tube.

The scanning of electron beam 14 in tubes A and B are effected lasfollows: The deflection signal is of such rising potential in relationto the potential impressed on deflecting plates 10 and 11 so that theelectron beam 14 in tube A is deflected to scan the variable conductanceinsulators 1, 2, and 3 before there is sufcient potential in thedeflection signal to cause the electron beam 14 in tube B to scan thevariable conductance insulators 4, 5, and 6. During the interval of timethat the electron beam 14 in tube A is bombarding the variableconductance insulator 1, 2, and 3, the electron beam 14 in tube B isdeflected to the right of the variable conductance insulator 4 untiljust after the electron beam 14 in tube A has finished bombarding thevariable conductance insulator 3. During the time interval that theelectron beam 14 in tube B is bombarding the variable conductanceinsulators 4, 5, and 6 the electron beam 14 in tube A is deflectedtowards the left of the Variable conductance insulator 3. When thevariable conductance insulators 4, 5 and 6 have been bombarded then thepotential of the vertical deflection signal returns to its originallevel and the cycle is repeated to scan the screen of cells from top tothe bottom. Tubes C and D operates in a similar manner to scan, fromleft to the right, the screen cells; tube D scans rst and tube C scansnext in the cycle and the said cycle is repeated.

The above is described to illustrate an example of the correlation ofthe various elements to produce the horizontal scanning of the cells ina direction similar to the horizontal scan of picture elements instandard television practice.

Out of 525 scanning lines in standard television practice, 470 linesrepresents active lines of picture elements; and, the picture ratio is 4to 3 each line totals 630 picture elements.

Using twelve cathode ray switching tubes, to represent the verticalcontrol of the line to be scanned, to cooperate in the manner of tubes Aand B; and sixteen cathode ray switching tubes, to represent thehorizontal control of each line of cells to be scanned, to cooperate inthe manner of tubes C and D; there will then be approximately fortyvariable conductance insulators in each tube; with the size andplacement of each of said variable conductance insulators in each tubeto be such as to allow for proper scanning of and insulation betweensaid variable conductance insulators. In each said tube one conductor isconnected fto each of the said variable conductance insulators with aseparate conductor connected to each. The conductors and the Variableconductance insulators can be assembled as one unit in a line and sealedin the tube; just as is now being done to seal in a glass tube blank.

The said cathode ray switching tubes can be one-half inch wide andarranged in four tube layers with a onehalf inch space between eachlayer. This will result in each layer of the vertical scanning controlto be three tubes in length, and, each layer of the horizontal controlof the scanning of the cells, representative of the picture ele-ments,to be four tubes in length. The layers would then appear as a frame fourinches deep.

Electric energy is transmitted from electric energy sources 20 and 21through each of said Variable conductance insulators to horizontalseparate electrodes 15 to electrodes 15A, and to vertical separateelectrodes 16 to electrodes 16A, respectively.

Electric energy source 20 is of positive potential and electric energysource 21 is of negative potential. Where photoelec-tric substances areplaced in each cell so as to modulate electric energy transmittedtherethrough to produce a signal, then the positive potential atelectric energy source is of, preferably, constant level to betransmi-tted through the variable conductance insulators 1-6 in tubes Aand B in FIG. 1 on said variable conductance insulators 1-6 beingbombarded by the electrons of the electron beam 14. Whereelectroluminescent substances are used to produce electroluminescence;the signal is impressed on the positive electric energy from source 20to be transmitted through the variable conductance insulators 1-6 intubes A and B in FIG. 1 on said variable conductance insulators beingbombarded by the electron beams 14.

Although it is now illustrated in drawing; it is not the practice tocontrol the intensity of the electron beam by the electron guns controlgrid, and, in accordance with the principle of electron bombardmentinduced conductance, the amount of electric energy transmittedtherethrough is in accordance with the amount of electron energy of theelectron beam impacted to the variable conductance insulators.

Referring to the variable conductance insulators in the cathode rayswitching tubes in FIGURES 1 and 5; where an insulating substance havingthe property to become conductive, such as a thin film of amorphoussilica, noted above, is deposited between an input electrode and anoutput electrode and is faced towards an electron gun projecting a highvelocity electron beam to bombard and penetrate the thin variableconductance insulator layer so as to vary its conductance in accordancewith the amount of electron beam energy absorbed by the said amorphoussilica.

Referring to FIGURE 2. The ultra-violet source 17 excites theelectrophotoluminescent layer, which can be as in FIGURES 1 and 5, andelectric field application produces enhanced clectroluminescence. Whereoptical element 18 is used and this is a camera screen, then screen inFIGURE 2 is used with photoconductive substances such as cadmium sullidein each cell. The cell can be of 0.1 mm. thick, and photoconductiveresponse to 5250A, 1within a width of 50 A., at 5000 V. cm. was twicethat for 3,000 v. cm., was effected with a sharp rise. The opticalelement focuses the images on the screen.

Referring to the drawings to describe an operation of the invention. -InFIGURE 1 the electron beam 14 in tube A is electrostaticallydeiilectedvby detlecting plate 9 which is impressed with a deflectionsignal from the vertical dellection signal generator 12 and ofsufficient potential so as to deflect the electron beam 14 to bombardthe variable conductance insulator 1 to cause the said variableconductance insulator 1 to become conductive. The electric energy source20 is of such positive potential level as to transmit electric energy toelectrode 15A in cell L in relation to the potential of the electricenergy on electrode 16A in cell L as to produce electroluminescence inphosphor between said elec-trodes in said cell. The said electric energyfrom source 20 is impressed with a signal and is transmitted through thevariable conductance insulator 1, due to the electron beam bombardmentthereon, to horizontal conductance 1S connected thereto to electrode 15Ain cell L so as to vary the luminescence in said phospho-r in image ofthe train of signal energy. The oth- -er deecting plate is electricallygrounded or of Sullicient potential with respect to the potential ondeilecting plate 10 to effect the bombarding of the variable ccnductanceinsulator therein when-desired.

At the same time the deilecting plates 9 in tubes C and D are impressedwith a dellection signal potential from the horizontal deflection signalgenerator 13 so that the electron beams 14 in each of said tubes isdellected in sequence so that in tube C it is to the left ot thevariable conductance insulator 4 and is aimed towards the container 7,and it is detlected in tube D to bombard the variable conductanceinsulator 1 to cause it to become conductive. The electric energy fromsource 21 is transmitted through the variable conductance insulator 1 intube D to vertical conductance or electrode 16 to electrode 16A. Theelectric energy source 21 is of such negative potential level as totransmit electric energy to electrode 16A in cell L in relation to thepotential of the electric energy on electrode A in cell L as to produceelectroluminescence in the phosphor between said electrodes in saidcell. The dellection signal potential gradually rises to dellect theelectron beam 14 to bombard the variable conductance insulators 2 and 3in turn in tube D.

The other dellecting plate 11 in tube C is impressed with a constantpotential suicient to prevent the electron beam 14 in said tube frombeing deflected to bombard the variable conductance insulator 4 untilthe potential on detlecting plate 9 in tube D has reached the pointwhere the electron beam 14 in said tube is deflected past the variableconductance insulator 3.

When the electron beam 14 in tube D is deflected past the variableconductance insulator 3, the electron beam 14 in tube C is deflected tobombard the variable conductance insulator 4, and as the dellectionsignal potential crises it dellects the electron beam 14 so as tobombard the variable conductance insulators 5 and 6 in turn. This Willcause electric energy to be impressed on cells M, N, O, P, and Q inturn.

The horizontal deflection potential level is now, as it is in practicenow done, brought to low potential level to cause the electron beam 14in tubes C and D to move completely to the left; and during thatinterval of time, as it is now done in practice, the signal energy isblanked Out.

The vertical detlecting signal gradu-ally rises to a higher potentiallevel and now dellects the electron beam 14 in tube A to bombard thevariable conductance insulator 2 to cause the transmission of signalmodulated electric energy from source 20 to conductance or electrode 15to electrode 15A in cell R. At the same time, the electron beam 14 intube D is deilected to bombard the variable conductance insulator 1 tocause the transmission of electric energy to conductance or electrode 16to electrode 16A in cell R to produce electrolumiuescence of thephosphor between electrodes 15A and 16A in cell R in image of the signalenergy impressed thereon during that interval of time that said electricenergy is transmitted to said cell R. The horizontal deflection signalpotential level gradually rises until all of t-he variable conductanceinsulators in tubes D and C are bombarded in turn to transmit electricenergy through vertical electrodes 16 to cells S, T, U, V, and W inturn. The above is repeated for each horizontal signal scan for eachvertical deilection to the next variable conductance insulator in tubesA and B in succession to completely scan the screen. The above can berepeated to effect a scanning of electric energy to the cells of thescreen in interlaced, line-by-l-ine or any other pattern. The electrodes1'5, 16 can be copper or any other good conducto-r, or transparentconductor.

Modication of the screen in FIGURE 2 is that the strips can be differentcolor phosphors.

FIGURE 4 schematically illustrates vertical transparent conductin-gstrips 23 and horizontal transparent conducting strips 2-4 connected tocathode ray switching tubes K and J as a modilication of the separateconductors 15 and 16 in FIG. l.

FIGURE 3 schematically illustrates another species of cells wherecathode ray switching tubes E and F transmit electric energy with adifference in potential from sources 20 and 21 to horizontal conductorsand verticalconductors 16, respectively, to their respective electrodesin each cell to give vertical direction to electric energy in each cell;and cathode ray switching tubes vG and H to transmit electric energywith a difference in potential from sources` 20 and 21 to horizontalconductors 15B and vertical conductors 16C, respectively, to theirrespective electrodes to give horizontal direction to electric energy toeach cell. The electron beams 14 in tubes E and G are deflected in turnand at equal time intervals to ellect two complete scannings of thescreen cells so as to bombard the variable conductance insulators 1, 2,and 3 in tube E for one complete scan and to bombard the variableconductance insulators 1, 2 and 3 in tube G during the next completescan as a cycle to be repeated; and the electron beam 14 in tubes F andH are dellected in turn and at equal time intervals to effect twocomplete scannings of the screen cells so as to bombard the variableconductance insulators 1, 2 and 3 in tube F for one complete scan and tobombard the variable conductance insulators 1, 2 and 3 in tube H duringthe next complete scan as a cycle to be repeated. During lthe timeinterval that tube E is operating, tube F is operating; and during theinterval of` time that tube G is operating, tube H is operating so thatalternate operation of tube combinations E and F, and, G and H, willeiect electric eld application in straight lines during each change, anda change in electric field application of at each change of operation.Luminescence can here be eilected, as noted above, by immersingelectroluminescent phosphors, excited by ultra-violet source least twopluralities of separate electrodes; an arrangement of one of eachelemental area of each separate electrode of one plurality of separateelectrodes in correlation with one elemental area of one separateelectrode of each other plurality of separate electrodes to be nearerand separated -from each other than the other elemental areas of eachsaid separate electrode; and means to generate, focus and direct atleast one electron beam of sufficient energy to vary the conductance ofsaid targets and to systematically and selectively bombard each of saidtargets with electrons whereby on said systematic and selective electronbombarding of each of said targets, electric energy is selectively andsystematically switched through selected separated electrodes.

2. The apparatus of claim 1 in which photoconductive substances areplaced within each of said correlated elemental areas.

3. The apparatus of claim 1 in which electroluminescent phosphors areplaced within each of said correlated elemental areas.

4. The apparatus of claim 3 in which the electroluminescent phosphorsare replaced by electrophotoluminescent phosphors; and, in addition, asource of radiant excitation energy adapted to irradiate theelectrophotoluminescent phosphors.

5. The apparatus of claim 4 in which the electric eld produced isalternately changed in 90 direction to each cell formed by eachelemental volume of electrophotoluminescent phosphors.

6. An electroluminescent display device comprises a screen to produce anelectroluminescent image comprising a plurality of separate electrodeswith each separate electrode associated with at least one other separateelectrode to form a combination of separated electrodes; elementalvolumes of electroluminescent phosphors arranged in a plane andinterposed between elemental areas of each said combination of separateelectrodes; each elemental volume of electroluminescent phosphorsinterposed between one elemental area of each separate electrode of eachsaid combination of separate electrodes; the elemental areas of eachsaid combination of separate electrodes having interposed therebetweennot more than one elemental volume of electroluminescent phosphors andeach separate electrode of each said combination is thereby associatedonly once with any other separate electrode of each said combination;and an electric energy apparatus in an evacuated space in combination aplurality of targets of variable conductance insulators, each targethaving separate electrodes electrically connected thereto and at leastone of said electrodes one of said plurality of separate electrodes;means to generate, focus and direct a plurality of electron beams, eachof suicient energy to Vary the conductance of said targets; and means todeect each electron beam in sequence to sequentially bombard a differentpredetermined number of said plurality of targets whereby electricity istransmitted through said targets and the electrodes electricallyconnected thereto, and the electric energy apparatus arranged as aborder of said screen.

7. An electroluminescent display device comprising a screen to producean electroluminescent image comprising a plurality of separateelectrodes with each separate electrode associated with at least oneother separate electrode to form a combination of separate electrodes;elemental volumes of electroluminescent phosphors arranged in a planeand interposed between elemental areas of each said combination ofseparate electrodes; each elemental volume of electroluminescentphosphors interposed between one elemental area of each said combinationof separate electrodes; the elemental areas of each said combination ofseparate electrodes having interposed therebetween not more than oneelemental volume of electroluminescent phosphors and each separateelectrodes of each said combination is thereby associated only once withany other separate electrode of each said combination; and an electricenergy apparatus in an evacuated space in combination a plurality oftargets of variable conductance insulators, each having separateelectrodes separately and electrically connected thereto, at least oneof said electrodes one of said plurality of separate electrodes; aplurality of electron beam generating, focusing and directing means,each electron beam of suicient energy to vary the conductance of saidtargets; deection signal source and deecting means to separately andsequentially detlect at least two electron beams, each to sequentiallyand systematically bombard a different predetermined number of saidtargets whereby electricity is transmitted through said targets and theelectrodes electrically connected thereto; and the electric energyapparatus arranged as a border of said screen.

8. A screen to produce an electroluminescent color image comprising aplurality of separate electrodes with each separate electrode associatedwith at least one other separate elect-rode to form a combination ofseparate electrodes; elemental volumes of electroluminescent phosphorarranged in a plane and interposed between elemental areas of eachcombination or separate electrodes; said electroluminescent phosphorsbeing a mixture of dilerent responsive and different color emittingelectroluminescent phosphors, each diterently responsive to a diierentfrequency of app-lied varying potentials; each elemental volume ofelectroluminescent phosphors interposed between one elemental area ofeach separate electrode of each combination of separate elec- Itrodes;the elemental areas of each combination of separate electrodes havinginterposed therebetween not more than one elemental volume ofelectroluminescent phosphors whereby each separate electrode in eachsaid combination is associated only once with any other separateelectrode in each combination.

9. A screen to produce an electroluminescent image comprising aplural-ity of separate electrodes with each separate electrodeassociated with `at least one other separate electrode tto form acombination of separate electrodes; electroluminescent cells arranged ina plane and interposed between elemental areas of each combination ofseparate electrodes; each electroluminescent cell interposed between oneelemental area of each separate electrode of each combination ofseparate electrodes; the elemental areas of each combination of separateelectrodes having interposed therebetween not more than oneelectroluminescent cell whereby each separate electrode in each saidcombination is associated only once with any other separate elect-rodein each combination; the electric potentials to initiateelectroluminescent light emission from each electroluminescent cell iseffected through the elemental areas .forming each electroluminescentcell; each cell comprising an electroluminescent light source ofelectroluminescent phosphors sandwiched between conductors; means totransmit a different potential to each conductor to initiate anelectroluminescent light emission Vby effecting a potential differenceand to stop the electroluminescent light emission by lowering lthepotential dierence; a photoemiss'ive layer adapted to be irradiated bysaid electroluminescent light emission to cause electrons to be emittedtherefrom; an electrode suitably placed to electrically impart velocityand direction to said emitted electrons; and a variable conductanceinsulator suitably positioned to be impacted by the accelerated anddirected electrons, said variable conductance insulator having separatedconductors electrically connected thereto for transmission of electriccurrent therethrough, one of said conductors electrically connected totransmit electric current to one of the conductors of theelectroluminescent cell whereby on applying potential `difference to theelectroluminescent cell to initiate electroluminescence therein to causephotoemissive llayer to emit electrons to be electrically acceleratedand directed to impact the vari- 9 able conductance insulator by aposi-tive potential impressed on the electrode, there would result atransmission of electric current through said variable conductanceinsulator to a conductor of the electrolurninescent cell to increasetthe intensity of electroluminescent light emission to effect a greateremission of electrons from the photoemissive layer to effect a greatertransmission of electric current to increase the electroluminescentlight emission and so increase the elect-roluminescent light emission inaccordance with time until stopped by lowering the potential diterencebetween the conductors causing stopping of electroluminescencetherebetween.

10. An electroluminescent cell comprising an electrolum-inescent lightsource of electrcluminescent phosphors sandwiched between conductors;means to transmit a different potential to each conductor to initiate anelectrolu'minescent light emission by effecting a potential differenceand to stop the electrolumtinescent light emission by lowering thepotential difference; a photoemissive layer adapted to be irradiated bysaid electroluminescent light emission to cause electrons to be emittedtherefrom; an electrode suitably placed to electrically impart velocityand direction to said emitted electrons; and a Variable conductanceinsulator suitably positioned to be impacted by the accelerated anddirected electrons, said variable conductance insulator having separatedconductors electrically connected thereto for transmission of electriccurrent therethrough, one of said conductors electrically connected totransmit electric current to one of the conductors of theelectroluminescent cell whereby on applying potential difference to theelectroluminescent cell to initiate eleetroluminescence therein to causephotoemission layer to emit electrons to be electrically `acceleratedand directed to impact the variable conductance insulator by a positivepotential impressed on t-he electrode, there would result a transmissionof electric current through said variable conductance insulator to aconductor of the electrolum-inescen-t cell References Cited by theExaminer UNITED STATES PATENTS 1,779,748 10/1930 rNicolson 315-1692,243,838 10/1938 Leverenz 250-80 2,515,931 7/1950 Six et al. 3162,559,279 7/1951 Charles B13-108.1 2,740,837 4/ 1956 Kirkpatrick.

3,102,242 8/1963 Matarese 250-213 OTHER REFERENCES Destriau: The NewPhenomenon of Electroluminescence, Philosophical Magazine, vol. 38, No.285, October 1947.

TAMES D. KALLAM, Acting Primary Examiner.

ARTHUR GAUSS, DAVID J. GALVIN, Examiners,

1. AN ELECTRIC ENERGY APPARATUS COMPRISING A SYSTEMATICALLY ARRANGEDPLURALITY OF TARGETS OF VARIABLE CONDUCTANCE INSULATORS, EACHELECTRICALLY CONNECTED TO TWO SEPARATED ELECTRODES; ONE OF EACH OF SAIDTWO SEPARATED ELECTRODES FORMING A GRID OF CROSSED ELECTRODES OF ATLEAST TWO PLURALITIES OF SEPARATE AREA OF EACH SEPARATE MENT OF ONE OFEACH ELEMENTAL AREA OF EACH SEPARATE ELECTRODE OF ONE PLURALITY OFSEPARATE ELECTRODES IN CORRALTION WITH ONE ELEMENTAL AREA OF ONESEPARATE ELECTRODE OF EACH OTHER PLUALITY OF SEPARATE ELECTRODES TO BENEARER AND SEPARATED FROM EACH OTHER THAN THE OTHER ELEMENTAL AREAS OFEACH SAID SEPARATE ELECTRDE; AND MEANS TO GENERATE, FOCUS AND DIRECT ATLEAST ONE ELECTRON BEAM OF SUFFICIENT ENERGY TO VARY THE CONDUCTANCE OFSAID TARGETS AND TO SYSTEMATICALLY AND SELECTIVELY BOMBARD EACH OF SAIDTARGETS WITH ELECTRONS WHEREBY ON SAID